This Outlook analyses key technological pathways, mainly constrained by GHG emission targets. By the nature of the exercise, these pathways are based on a large number of educated assumptions about the evolution of technologies and associated costs. Yet over the last few years, many of the recent certainties about GHG emissions, including the role of nature-based solutions, have undergone massive re-evaluations. Similarly, technical developments have often been shown to be fickle: promising technologies that fail to deliver on a large scale, while unexpected new approaches transform entire economic sectors. This chapter explores the impact of modifying some of these assumptions, which are by default built on what we know or expect and the time, to attempt to integrate some of these unexpected transformations in core energy transition issues. Variable renewable electricity, provided by wind and solar generation, constitutes virtually all of the very significant increase in electricity generation needed to meet demand in the net-zero scenarios explored in this Outlook. Correctly modelling their integration is challenging and technical and economic uncertainties remain in relation to nuclear SMRs, utility-scale battery storage, and ancillary costs for grids with high levels of variable generation. Added to these are the uncertainties respecting social acceptability constraints on nuclear and large hydro development, as well as strategic considerations applicable to grid resilience and political orientation. Results from the sensitivity analysis show that while total demand for electricity is not affected by the nature of the energy source, the evolution of
these factors will affect the type of infrastructure needed. For example, increased provincial exchanges of electricity provide an important way to reduce pressure on the grid in terms of the necessary capacity installed; similarly, less variable generation can be accommodated by more hydro and nuclear installations.
Biomass availability, which is the focus of much debate and many scientific studies, also turns out to be a major factor in shaping net-zero futures. The sensitivity analysis conducted shows how useful bioenergy can be in efforts to reduce emissions, underlining how critical it is to very carefully manage this resource if its potential is to be tapped into.
Uncertainties about the role that hydrogen will play in the future make it difficult to draw a bottom line today. Exploratory scenarios showed how hydrogen can play an increased role in different sectors without jeopardizing the achievement of net-zero emissions. However, negative emission production with BECCS remains constrained by biomass availability.
Finally, with the current state of technologies, reaching and maintaining net-zero emissions will require significant amounts of carbon capture. Here, both costs and technological uncertainties serve as an important warning that projections may be too optimistic, and that an even greater quantity of DAC and negative emissions energy production (which significantly is constrained by biomass availability) may be required to compensate for optimism on the share of emissions that can be captured in the various processes. This adds to the risks and current unknowns of continued large-scale storage. While technological improvements may temper some of these risks over time, devoting at least as much effort to innovation in emission reductions as to capture seems essential.
Naturally, the technological pathways discussed above do not exist in isolation: biomass availability not only increases the ability to deal with short-term reductions where technology remains expensive, but also results in the opportunity to produce more hydrogen with negative emissions, increasing its overall consumption. More hydrogen helps decarbonize applications where electricity struggles and could provide an alternative in terms of storage. The importance of social acceptability issues surrounding nuclear facilities and the construction of additional large-scale hydroelectric dams may also affect the prospects for a greater use of biomass. Resolving these uncertainties will thus take time and strategic choices over which pathway(s) to focus on may be required before they are entirely eliminated.